The objective of this study is to obtain longitudinal descriptive data on the experiences of families with first born infants. Three groups of families will be studied: those in which the mother plans to be the full time caregiver for the infant during its first year; families in which the mother is employed when the baby is 3 months old; and families in which the mother plans to be employed before the baby's first birthday, but is not employed when the baby is 3 months old. At 3 months and again at 12 months, two observations will be carried out in the families' homes when mother, father and baby are together; parents will also be interviewed and will be asked to complete a Q sort to measure their perceptions of their infant temperament. In addition, a single observation will be carried out with mother and baby alone if the mother is not employed. Data analysis will consist of cross-sectional and longitudinal comparisons of the three groups, and comparisons of babies' interactions with mothers and with substitute caregivers.